Lead Mobile Frontend Engineer

About the role Calibrex is on a mission to democratize fitness coaching by giving everyone access to a world-class personal trainer for less than the cost of Netflix. We’re building GPS-like guidance for fitness: clear direction at every step, without excuses or guesswork. All you have to do is show up. As a Lead Mobile Frontend Engineer, you’ll help build the product that makes this mission possible. You’ll work directly with athletes, influencers, and leaders across fitness and professional sports while shaping the UX and direction of the app. You’ll also work out in our office gym, collaborate with an elite team in one of the fastest-growing spaces in technology, and enjoy high-protein catered meals, a premium gym membership at Life Time or Equinox, and an office located three blocks from Grand Central. Calibrex offers an annual performance-based cash bonus and a generous equity package. The role includes great benefits and is an excellent wealth-building opportunity at a fast-growing pre-IPO company in a nascent and extremely exciting space. What you’ll bring 3+ years of professional experience developing mobile applicationsExperience building or maintaining mobile apps used by 100,000+ usersStrong React Native and TypeScript experienceAbility to turn Figma designs into polished, production-ready mobile flowsStrong understanding of React hooks, API calls, asynchronous data, state management, and error handlingHigh standard for mobile performance, usability, and interaction qualityComfort using AI tools for development, prototyping, debugging, and testingAbility to work independently and provide technical leadershipStrong communication and collaboration skillsMust regularly work out or train and be comfortable testing the app in our office gym; this is an essential part of the role Core skills React Native | Expo/EAS | Github | Figma to Code | React hooks | API integration | State Management | AI-Assisted Development | Loop Engineering | Mobile Testing | Firebase Preferred experience Shipped a consumer mobile app at meaningful scaleUsed ExpoLed frontend architecture or mentored other engineersBuilt automated mobile testing or performance-monitoring workflowsWorked at an Early-Stage startupContributed to product strategy or UX direction